<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
  <a class="navbar-brand" href="/">Navbar</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>

  <div class="collapse navbar-collapse" id="navbarsExampleDefault">
    <ul class="navbar-nav mr-auto">
    	<li class="nav-item">
        <a class="nav-link" href="/home">Home </a>
      </li>
      {{if  user && user.id}}
      <li class="nav-item">
        <a class="nav-link" href="/users/loginOut">注销</a>
      </li>
      {{else }} 
      <li class="nav-item">
        <a class="nav-link" href="/users/login">登录</a>
      </li>  
      {{/if}}  
      <li class="nav-item">
        <a class="nav-link" href="/publish/toAdd">发表</a>
      </li>
    </ul>
    <form class="form-inline my-2 my-lg-0">
      <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>
</nav>